Feeds

World's most advanced rootkit penetrates 64-bit Windows

Windows driver signing mincemeat

Top 5 reasons to deploy VMware with Tegile

A notorious rootkit that for years has ravaged 32-bit versions of Windows has begun claiming 64-bit versions of the Microsoft operating system as well.

The ability of TDL, aka Alureon, to infect 64-bit versions of Windows 7 is something of a coup for its creators, because Microsoft endowed the OS with enhanced security safeguards that were intended to block such attacks. The rootkit crossed into the 64-bit realm sometime in August, according to security firm Prevx.

According to research published on Monday by GFI Software, the latest TDL4 installation penetrates 64-bit versions of Windows by bypassing the OS's kernel mode code signing policy, which is designed to allow drivers to be installed only when they have been digitally signed by a trusted source. The rootkit achieves this feat by attaching itself to the master boot record in a hard drive's bowels and changing the machine's boot options.

“The boot option is changed in memory from the code executed by infected MBR,” GFI Technical Fellow Chandra Prakash wrote. “The boot option configures value of a config setting named 'LoadIntegrityCheckPolicy' that determines the level of validation on boot programs. The rootkit changes this config setting value to a low level of validation that effectively allows loading of an unsigned malicious rootkit dl file.”

According to researchers at Prevx, TDL is the most advanced rootkit ever seen in the wild. It is used as a backdoor to install and update keyloggers and other types of malware on infected machines. Once installed it is undetectable by most antimalware programs. In keeping with TDL's high degree of sophistication, the rootkit uses low-level instructions to disable debuggers, making it hard for white hat hackers to do reconnaissance.

One of the advanced protections Microsoft added to 64-bit versions of Windows was kernel mode code signing policy. Microsoft also added a feature known as PatchGuard, which blocks kernel mode drivers from altering sensitive parts of the Windows kernel. TDL manages to circumvent this protection as well, by altering a machine's MBR so that it can intercept Windows startup routines.

Prevx has more here. And for an in-depth technical analysis from Microsoft researcher Joe Johnson check out this PDF. ®

Remote control for virtualized desktops

More from The Register

next story
Patch NOW! Microsoft slings emergency bug fix at Windows admins
Vulnerability promotes lusers to domain overlords ... oops
Mozilla, EFF, Cisco back free-as-in-FREE-BEER SSL cert authority
Let’s Encrypt to give HTTPS-everywhere a boost in 2015
You really need to do some tech support for Aunty Agnes
Free anti-virus software, expires, stops updating and p0wns the world
Meet OneRNG: a fully-open entropy generator for a paranoid age
Kiwis to seek random investors for crowd-funded randomiser
Got an iPhone or iPad? LOOK OUT for MASQUE-D INTRUDERS
UNjailbroken iOS 7, 8 open to evil, says secbiz FireEye
USB coding anarchy: Consider all sticks licked
Thumb drive design ruled by almighty buck
Attack reveals 81 percent of Tor users but admins call for calm
Cisco Netflow a handy tool for cheapskate attackers
prev story

Whitepapers

Choosing cloud Backup services
Demystify how you can address your data protection needs in your small- to medium-sized business and select the best online backup service to meet your needs.
Getting started with customer-focused identity management
Learn why identity is a fundamental requirement to digital growth, and how without it there is no way to identify and engage customers in a meaningful way.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Simplify SSL certificate management across the enterprise
Simple steps to take control of SSL across the enterprise, and recommendations for a management platform for full visibility and single-point of control for these Certificates.
Saudi Petroleum chooses Tegile storage solution
A storage solution that addresses company growth and performance for business-critical applications of caseware archive and search along with other key operational systems.